Various fields of research, such as functional genomics, basic life science research, drug discovery and clinical diagnostics, require studying of the molecular mechanisms of a sample, e.g. monitoring of different aspects of oligonucleotides, cDNA or protein interaction. In order to study molecular mechanisms, a microarray-based assay can be used, e.g. an optical assay, such as a fluorescent or a phosphorescent binding assay.
An assay may be performed by a microarray of spots of probe molecules attached to distinct locations on a slide forming a support, the spots of probe molecules providing binding sites for the target molecules of the sample to be analyzed. The diameter of the spots on a microarray support is typically between 50 micrometer and 300 micrometer and normally 100-150 micrometers, and the thickness of the spots are normally only a few micrometer and usually less than 10 micrometer. When a sample, containing e.g. fluorescent-labeled targets, is brought in contact with the spots on the microarray support, the target molecules in the sample is allowed to hybridize with the probe molecules of the spots. In a fluorescent assay, the microarray support is illuminated by an exciting light source and the position and the intensity of the emitted fluorescent light is  detected. The color of the used fluorophore serves as a marker indicating that a reaction has occurred between target molecules of the sample and probe molecules of the spots. The optical means for illuminating the support and detecting the light emitted from the support may include a microarray scanner or a microarray imager.
A scanner comprises a narrowband exciting light source, e.g. a laser, and e.g. a PMT (photomultiplier tube) for detecting emitted light. An imager comprises a wideband exciting light source, e.g. a xenon lamp, wavelength filters to provide monochromatic light, and a detector for the emitted light, e.g. a CCD (Charged-Coupled Device).
In microarray technology, there are several benefits by employing polymeric slides for manufacturing of a microarray support instead of glass slides. One of the benefits is that polymeric slides can have a higher density of surface silanol groups than glass slides, which enhances the number of reactive groups participating in the binding process of the probe to the slide, resulting in a higher surface coverage of binding sites. Additionally, polymers exhibit a wider spectrum of properties and are easier to modify, thereby achieving a higher binding capacity. Also, the non-specific binding on polymer slides is normally lower than on glass slides. Furthermore, a higher degree of immobilization is possible on polymer slides, even without UV-crosslinking or blocking, requiring no prehybridization.
However, a drawback with the use of polymer slides is that a higher background signal occurs from autofluorescence in comparison with glass slides.
Prior art in the field of microarray supports is disclosed in WO 01/94032, describing enlargement of the surface of a support by providing pyramidical or conical indentations therein, achieving  an increased surface available for the probe. Consequently, an increased number of binding sites may be provided, thereby increasing the signal-to-noise ratio. By surface enlarging patterns, an increase of the available surface area by a factor 2 or 3 is easily obtained, in comparison with planar supports.
US 2002/0028451 describes a detection apparatus comprising a polymeric support substrate provided with microstructured grooves, onto which a liquid crystal material is applied. The size of the grooves is selected to cause the liquid crystal material to adopt a uniform orientation, such that the adherence of particles will be optically detectable by causing a disruption of the uniform orientation.
Further prior art relating to polymeric support provided with high-precision microfeatures is disclosed e.g. in EP 0714742.
However, since there is a need for further improvement of microarray-based optical assays, an object of this invention is to provide an improved polymeric microarray support, achieving a further improved performance of optical assays compared to prior art, e.g. regarding the signal-to-noise ratio.